The present invention relates to a child seat to be set on a seat of a car such that a sitting occupant such as an infant faces the rear of the car.
There is an ISO-FIX child seat standardized in the International Organization for Standardization as a child seat to be set in a car (for example, Japanese Unexamined Patent Application Publication No. 2004-106668).
In the ISO-FIX child seat described in the same publication, a child seat is mounted on a seat cushion and the lower portion (base) of the child seat is joined to an anchor bar provided on a car body.
When the speed of a car is suddenly reduced by a head-on collision (including an offset collision) and etc., the inertia of a child seat set on a seat of the car is applied to move the child seat toward the front of the car. When the lower portion of the child seat is bound to the car seat and the speed is suddenly reduced, the upper portion of the child seat moves forward in such a way that the upper portion of the child seat falls toward the front of the car.
In order to prevent such a forward movement of the upper portion of a child seat, it is proposed that the upper portion of a child seat is joined to a car member, seat back, etc., positioned in the rear of the car behind the child seat (for example, Japanese Unexamined Patent Application Publication No. 2003-191780).
In the above-described Japanese Unexamined Patent Application Publication No. 2003-191780, a child seat is set on a car seat to face the front of the car so that the occupant of the child seat may face the front of the car, a tether extended toward the rear of the car from the upper portion of a seat back portion of the child seat is pulled over the seat back of the car seat, and the tether is latched onto a hook provided on the back surface of the seat back of the car seat. Then, the seat back portion of the child seat is fixed so as to be pressed against the seat back of the car seat by making the tether tense.
In this way, even when the speed of the car is suddenly reduced by a head-on collision, etc., since the upper portion of the child seat is pulled toward the rear of the car by the tether, a circular forward movement of the child seat toward the front of the car is prevented or suppressed.
In the above-described Japanese Unexamined Patent Application Publication No. 2003-191780, a child seat is set to face the front of a car on a car seat and the seat back portion of the child seat is in contact with the seat back of the car seat, and accordingly, a tether joining these portions is relatively short.
On the contrary, when a child seat is set to face the rear of the car so that the occupant of the child seat may face the rear of the car, since the seat base portion of the child seat is disposed between the seat back portion of the child seat and the seat back of the car seat, they are separated widely. Accordingly, it is necessary to make a tether long for joining the seat back portion of the child seat and the seat back of the car seat. However, when the tether is long, the tether can easily become loose.
It is an object of the present invention to provide a child seat constructed in such a way that, when the child seat is set to face the rear of the car on a car seat, the child seat is capable of being securely fixed on the car seat.